Impact of socio-economic status on breast cancer screening in women with diabetes: a population-based study

AIMS

There is evidence to suggest that mammography rates are decreased in women with diabetes and in women of lower socio-economic status. Given the strong association between low socio-economic status and diabetes, we explored the extent to which differences in socio-economic status explain lower mammography rates in women with diabetes.

METHODS

A population-based retrospective cohort study in Ontario, Canada, of women aged 50 to 69 years with diabetes between 1999 and 2010 age matched 1:2 to women without diabetes. Main outcome measure is the likelihood of at least one screening mammogram in women with diabetes within a 36-month period, starting as of either 1 January 1999, their 50th birthday, or 2 years after diabetes diagnosis--whichever came last. Outcomes were compared with those in women without diabetes during the same period as their matched counterparts, adjusting for socio-economic status based on neighbourhood income and other demographic and clinical variables.

RESULTS

Of 504,288 women studied (188,759 with diabetes, 315,529 with no diabetes), 63.8% had a screening mammogram. Women with diabetes were significantly less likely to have a mammogram after adjustment for socio-economic status and other factors (odds ratio 0.79, 95% CI 0.78-0.80). Diabetes was associated with lower mammogram use even in women from the highest socio-economic status quintile (odds ratio 0.79, 95% CI 0.75-0.83).

CONCLUSIONS

The presence of diabetes was an independent barrier to breast cancer screening, which was not explained by differences in socio-economic status. Interventions that target patient, provider, and health system factors are needed to improve cancer screening in this population.

Socioeconomic status and risk of hospitalization among individuals with cystic fibrosis in Ontario, Canada

BACKGROUND

Socioeconomic status (SES) is a strong predictor of outcomes in cystic fibrosis (CF); however, there are no published studies evaluating this relationship in Canadians with CF. The objective of this study was to assess the effect of SES on annual hospitalization rates in a large cohort of pediatric and adult CF subjects under a universal health care system.

METHODS

A population-based longitudinal study was completed in Ontario from 1993 to 2002 using a comprehensive CF registry containing patient-level data, linked to provincial health care administrative databases. Income quintiles were derived at the neighborhood level using postal code information and Statistics Canada census data. The effect of income quintile on the annual hospitalization rate for respiratory-related illness was estimated by Poisson regression using generalized estimating equations, and was expressed as a rate ratio (RR) and 95% confidence interval (CI). The analysis was adjusted for age, sex, lung function, nutritional status, the presence of diabetes, area of residence, and distance between the subject's residence and the reporting CF centre.

RESULTS

A total of 1,174 participants over the age of 6 years contributed 8,444 patient-years of data. No statistically significant differences in annual hospitalization rates for respiratory-related causes were found between the lowest and highest income quintiles (adjusted RR 1.17 [95% CI 0.96-1.43]). The effect of income quintile remained non-significant across a majority of markers of CF disease severity and across a range of subgroups.

CONCLUSIONS

After adjusting for important covariates, no SES-disparities in hospitalization rates were found in a large Canadian pediatric and adult CF cohort. It may be the distinctive combination of universal health care, a national network of specialty CF clinics, and drug and travel coverage available in Ontario that results in similar hospitalization rates regardless of SES.

Risk of acute complications of diabetes among people with schizophrenia in Ontario, Canada

OBJECTIVE

Diabetes mellitus (DM) is a complex, chronic disease requiring active self-management and coordinated care. This study aimed to evaluate the relationship between schizophrenia and risk of preventable, acute DM complications.

RESEARCH DESIGN AND METHODS

With the use of administrative data, a retrospective study assessed acute DM complications (emergency department [ED] visits or hospitalization for hypo- or hyperglycemia and hospital admissions for infections) among Ontario residents ages 18-50 with schizophrenia and newly diagnosed DM between 1995 and 2005, comparing people with and without pre-existing schizophrenia. Primary outcome was ED visit or hospitalization for hypo- or hyperglycemia. Secondary outcome was the first of either the primary outcome or hospitalization for infection.

RESULTS

People with schizophrenia had a 74% greater risk of requiring a hospital visit for hypo- or hyperglycemia (hazard ratio [HR] = 1.74, 95% confidence interval 1.42-2.12) compared with those without schizophrenia. The risk was similar when the outcome included infection (HR = 1.62, 95% CI 1.39-1.89). Outcomes remained significant after adjustment for baseline characteristics.

CONCLUSIONS

People with schizophrenia are at greater risk for developing an acute complication of DM. Understanding this relationship will direct future studies assessing barriers to care and implementation of individualized approaches to care for this population.

An investigation of satellite hemodialysis fallbacks in the province of Ontario

BACKGROUND AND OBJECTIVES

In Ontario, Canada, hemodialysis services are organized in a "hub and spoke" model comprised of regional centers (hubs), satellites, and independent health facilities (IHFs; spokes). Rarely is a nephrologist on site when dialysis treatments take place at satellite units or IHFs. Situations occur that require transfer of the patient back ("fallbacks") to the regional center that necessitate either in- or outpatient care. Growth in the satellite dialysis population has led to an increased burden on the regional centers. This study was carried out to determine the incidence, nature, and outcome of such fallbacks to aid resource planning.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were collected on 565 patients from five regional centers over 1 yr. These regional centers controlled 19 satellite dialysis centers including 7 IHFs.

RESULTS

There were 681 fallbacks in 328 patients: 1.21 incidents per patient or 2.1 incidents per patient year. Multiple fallbacks occurred in 170 patients. Fallback episodes lasted a mean of 10.3 d, requiring 4.6 dialysis treatments. Forty-five percent of fallbacks required hospitalization with a mean stay of 16.7 d. Access-related problems (33%) and nondialysis medical causes (32%) were the major causes of fallback. Resolution of the problem occurred in 87.8%, with the patient returning to the satellite. By the end of the study 77.3% were still satellite patients, 10.8% died, 3.8% returned to the regional center, 3.4% were transplanted, and 4.7% were transferred to other treatment modalities.

CONCLUSIONS

Fallbacks are common, yet the model operates well.

Exercise interventions in obese youth: are they effective?

Given the increasing prevalence of childhood obesity, effective and cost-efficient strategies to enhance children's physical activity levels are needed. Unfortunately, exercise interventions evaluated to date have had little impact on overweight and obesity in youth. Physical activity counseling interventions have emerged as an effective and inexpensive alternative to traditional, structured exercise programs in adults, and may be an interesting option for the treatment of obesity in youth.

Using multiple data features improved the validity of osteoporosis case ascertainment from administrative databases

OBJECTIVES

The aim was to construct and validate algorithms for osteoporosis case ascertainment from administrative databases and to estimate the population prevalence of osteoporosis for these algorithms.

STUDY DESIGN AND SETTING

Artificial neural networks, classification trees, and logistic regression were applied to hospital, physician, and pharmacy data from Manitoba, Canada. Discriminative performance and calibration (i.e., error) were compared for algorithms defined from different sets of diagnosis, prescription drug, comorbidity, and demographic variables. Algorithms were validated against a regional bone mineral density testing program.

RESULTS

Discriminative performance and calibration were poorer and sensitivity was generally lower for algorithms based on diagnosis codes alone than for algorithms based on an expanded set of data features that included osteoporosis prescriptions and age. Validation measures were similar for neural networks and classification trees, but prevalence estimates were lower for the former model.

CONCLUSION

Multiple features of administrative data generally resulted in improved sensitivity of osteoporosis case-detection algorithm without loss of specificity. However, prevalence estimates using an expanded set of features were still slightly lower than estimates from a population-based study with primary data collection. The classification methods developed in this study can be extended to other chronic diseases for which there may be multiple markers in administrative data.

Impact of a fluoroquinolone restriction policy in an elderly population

BACKGROUND

In light of growing concerns of bacterial resistance to fluoroquinolones, the province of Ontario instituted a fluoroquinolone restriction policy in March of 2001. The objective of this study was to examine the immediate impact of this policy on the rates of antibiotic prescription use and infectious disease-related hospitalizations among elderly individuals who are dispensed antibiotics.

METHODS

An interrupted time series analysis was conducted from January 1, 1994, to March 31, 2002, using administrative health care databases covering more than 1.4 million residents of Ontario, Canada, aged 65 years and older. Population rates of antibiotic use and infectious disease-related hospitalizations within 4 weeks after an antibiotic prescription were examined using interventional autoregressive integrated moving average models.

RESULTS

Immediately after the introduction of the fluoroquinolone policy, fluoroquinolone prescription rates decreased to approximately 70% of expected rates (P<.01). Approximately 30% higher than expected use of sulfonamide (P=.01) and urinary anti-infectives (primarily nitrofurantoin and trimethoprim; P<.01) were observed within 1 year after policy implementation. No significant changes in the use of any other groups of antibiotics were observed. Although no significant changes in the rates of overall infection-related hospital admissions among antibiotic users were observed, the rate of hospital admission for gastrointestinal infections was 32% lower than expected in the 1 year after the policy change (P<.01). The hospital admission rate for urinary tract infections was approximately 8% higher than expected (P<.01).

CONCLUSIONS

These findings suggest that formulary restrictions to fluoroquinolones can be implemented effectively to decrease use among an elderly population without adverse impact on hospital admission rates.

Quantification of the Risk of Corticosteroid-induced Diabetes Mellitus Among the Elderly

We conducted a population-based cohort study using administrative databases to quantify the association between oral and inhaled corticosteroid use and onset of diabetes mellitus in the elderly. Proton pump inhibitor (PPI) users were used as a control group. Relative to PPI users (N = 53,845), oral corticosteroid users (N = 31,864) were more likely to develop diabetes (adjusted rate ratio [aRR], 2.31; 95% confidence interval [95% CI], 2.11 to 2.54); however, inhaled corticosteroid users (N = 38,441) were not (aRR, 1.03; 95% CI, 0.93 to 1.14). The estimated number needed to harm for continuous use of oral corticosteroids relative to PPIs over 1, 2, and 3 years of use were 41, 23, and 16, respectively.

Proton pump inhibitors. Compliance with a mandated step-up program

OBJECTIVE

To assess compliance with a step-up approach to proton pump inhibitor (PPI) therapy before implementation of a new provincial policy to promote histamine-type 2 receptor antagonist (H2RA) use before PPI therapy.

DESIGN

Population-based, retrospective, open cohort study using prescribing and medical procedure data from January 1, 1995, to April 30, 1999.

SETTING

Health administration databases for the universal health care system in Ontario.

PARTICIPANTS

Approximately 1.4 million residents of Ontario older than 65 years.

MAIN OUTCOME MEASURES

Proportion of patients who received a trial of H2RA therapy or gastrointestinal diagnostic testing 12 months before starting PPI therapy in 1996.

RESULTS

Among the 25,870 patients who met study criteria in 1996, about 63% had received H2RAs 12 months before starting PPI therapy and 73% had had a trial of H2RAs or gastrointestinal diagnostic testing. Repeat analysis for January through April 1999, following the new policy implementation, showed that about 72% of patients had had a trial of H2RAs within 12 months of starting PPI therapy.

CONCLUSION

A modest gain (9%) in compliance with using H2RA therapy within 12 months before starting PPI therapy was seen following introduction of the step-up intervention. In future, costs and benefits of potential interventions should be carefully considered before implementing new policies.